Kurzfassung

Objectives: This study evaluates liquid-rubber-coating to prevent moisture loss in bone during long-term biomechanical testing and digital image correlation (DIC) measurements. Can liquid-rubber-coating preserve bone mechanical properties and enhance DIC measurements?Methods: Two experimental series used porcine femora in a 4-point-bending setup (n=6). Series 1 compared dehydration with and without rubber-coating during a 21-h drying period, focusing on bending stiffness and weight loss. Series 2 compared liquid-rubber-coating to acrylic-paint for DIC measurements across 50-2,000 & micro;epsilon principal strain. Results: After 21 h, weight loss of the uncoated samples was almost three times higher (7.9 +/- 0.4 % vs. 2.9 +/- 0.6 %, p<0.001). Bare samples increased bending stiffness by 16.3 +/- 4.7 % (p=0.003) vs. 5.8 +/- 4.0 % (p=0.155) with coating. DIC noise was 174 +/- 121 & micro;epsilon with acrylic-coating and 158 +/- 113 & micro;epsilon with liquid-rubber (p=0.700). Bland-Altman analysis showed no significant differences between the groups (p >= 0.128). Conclusions: The liquid-rubber-coating substantially reduced moisture loss and maintained bone mechanical properties over 21 h, without significant alteration to mechanical properties. DIC performance showed no consistent coating-related differences, indicating the coating as a time-stable, water-impermeable alternative to acrylics. Notably, coated samples exhibited reduced odour. Future work should test liquid-rubber-coatings under physiological loading in human bone to improve DIC accuracy for finite element validation and digital twin precision.